Merge tag 'mtd/for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux

[linux.git] / samples / bpf / xdp_fwd_user.c

diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c
index 5b46ee12c696c69839817226aef0d2e54f0858f9..97ff1dad766978601eaaf2da9a5a6752b86cfd98 100644 (file)
--- a/samples/bpf/xdp_fwd_user.c
+++ b/samples/bpf/xdp_fwd_user.c
@@ -27,14 +27,20 @@
 #include "libbpf.h"
 #include <bpf/bpf.h>
 
-
-static int do_attach(int idx, int fd, const char *name)
+static int do_attach(int idx, int prog_fd, int map_fd, const char *name)
 {
        int err;
 
-       err = bpf_set_link_xdp_fd(idx, fd, 0);
-       if (err < 0)
+       err = bpf_set_link_xdp_fd(idx, prog_fd, 0);
+       if (err < 0) {
                printf("ERROR: failed to attach program to %s\n", name);
+               return err;
+       }
+
+       /* Adding ifindex as a possible egress TX port */
+       err = bpf_map_update_elem(map_fd, &idx, &idx, 0);
+       if (err)
+               printf("ERROR: failed using device %s as TX-port\n", name);
 
        return err;
 }
@@ -47,6 +53,9 @@ static int do_detach(int idx, const char *name)
        if (err < 0)
                printf("ERROR: failed to detach program from %s\n", name);
 
+       /* TODO: Remember to cleanup map, when adding use of shared map
+        *  bpf_map_delete_elem((map_fd, &idx);
+        */
        return err;
 }
 
@@ -67,10 +76,10 @@ int main(int argc, char **argv)
        };
        const char *prog_name = "xdp_fwd";
        struct bpf_program *prog;
+       int prog_fd, map_fd = -1;
        char filename[PATH_MAX];
        struct bpf_object *obj;
        int opt, i, idx, err;
-       int prog_fd, map_fd;
        int attach = 1;
        int ret = 0;
 
@@ -103,8 +112,14 @@ int main(int argc, char **argv)
                        return 1;
                }
 
-               if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
+               err = bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd);
+               if (err) {
+                       printf("Does kernel support devmap lookup?\n");
+                       /* If not, the error message will be:
+                        *  "cannot pass map_type 14 into func bpf_map_lookup_elem#1"
+                        */
                        return 1;
+               }
 
                prog = bpf_object__find_program_by_title(obj, prog_name);
                prog_fd = bpf_program__fd(prog);
@@ -113,16 +128,12 @@ int main(int argc, char **argv)
                        return 1;
                }
                map_fd = bpf_map__fd(bpf_object__find_map_by_name(obj,
-                                                                 "tx_port"));
+                                                       "xdp_tx_ports"));
                if (map_fd < 0) {
                        printf("map not found: %s\n", strerror(map_fd));
                        return 1;
                }
        }
-       if (attach) {
-               for (i = 1; i < 64; ++i)
-                       bpf_map_update_elem(map_fd, &i, &i, 0);
-       }
 
        for (i = optind; i < argc; ++i) {
                idx = if_nametoindex(argv[i]);
@@ -138,7 +149,7 @@ int main(int argc, char **argv)
                        if (err)
                                ret = err;
                } else {
-                       err = do_attach(idx, prog_fd, argv[i]);
+                       err = do_attach(idx, prog_fd, map_fd, argv[i]);
                        if (err)
                                ret = err;
                }